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jato gearing issue

i have recently put an integy alum. transmission case and alum. shock towers on my jato 3.3. and. ive heard that because of added weight you need to change gear ratio. what would be a good ratio or how many teeth do my spur gear and clutch bell have to be?

Spur gears are really cheap, there only $2-3. I recommend getting several different sizes so you can play around with them and find the perfect gear ratio for your needs. I like using low gears for off road and A higher ratio for street.

You change the gear ratio by replacing the clutch bell on the motor or the spur gear on the transmission or both. The stock gears on the Jato are 24/54. A lower ratio will increase take off and acceleration while reducing top speed. You achieve this by putting on A larger spur gear or A smaller clutch bell. Off road I use A 5" tire instead of the stock 4" which raises the gear ratio to A higher one. So I use A 21 tooth clutch bell and A 56 tooth spur gear to keep the rpm to speed ratio near stock. On road I use A 24/53 ratio to get a little more top end and more control on take off. But be warned using A higher gear ratio will put more strain on the drivetrain causing stripped gears and twisted driveshafts. And be careful with lower gears too, it makes it easier to over rev the engine. If you use lower gears for more power than you need to reset the shift point for 2nd gear as the transmission will not be spinning as fast per rpm of the motor as it was stock.

Wow, lot of info in my opinion, thanks btw. Just to clarify, the stock gears are 24/54 (sorry to repeat what you said but I'm just trying to fully understand) which mathematically I broke down to 24 divided by 54 which equals a ratio of .44. I also divided the other way 54/24 equals a ratio of 2.25. And your off road ratio would be 2.66 (56 divided by 21) and on-road would be 2.20( 53 divided by 24) so with the my added weight and
getting some better tires ( I'm thinking pro-line trenchers or I heard badlands were good also) so i would probably want my gear ratio any where from 2.3 to possibly 2.7 or higher? (please correct me if I'm wrong) as of right now I have an integy 55t spur gear that was giving to me as a gift. If my calculations are correct I would use a 24, 22 or 20 clutch bell wich would give me a ratio of 2.29(24). 2.5(22) and 2.75(20) so either the 22t or 20t clutch would give better performance due to added weight after that then I just have to play with both and see which one seems better...?

You've got it. I wouldn't be so concerned with a little more weight. Some of the trucks that come with the 3.3 weigh over 10lbs. The Jato comes in around 5lbs. The few ounces added by A couple of aluminum parts don't matter enough to notice.

Easier way to think is this: on your 21-speed mountain bike the pedals are attached to the front gearset (clutch bell) and the rear gearset is the spur gear. Go from big to small on the front and what happens? Small to big? Same with the rear. Think of how hard it is to pedal in each of the gears.
Taking the gears and dividing them out is another way. The lower the number the more top speed. The higher the number the more acceleration.